1. Field of the Invention
The present invention relates to a tool for releasing a fastening device which can be attached to an article or articles in such a manner that the device can be separated only by use of the tool located, for example, at a checkout point in a department store or the like. In particular, the present invention relates to such a tool which can easily be secured against use by non-authorized personnel.
2. Discussion of Related Art
Identification tags are known which contain electric circuits. These tags can be secured to clothing or other articles on sale in a department store to act as anti-theft monitors. Special receiving equipment is positioned at the exits of the store and is activated when one attempts to remove a garment with an attached tag.
The tag assembly is temporarily attached to an article prior to authorized handling and sale of such article, at which time, the identification tag is removed. Fastening devices which can be used to effect this type of attachment are well known and an example of such is described in U.S. Pat. No. 3,974,581 to Martens et al. The Martens et al fastener operates by inserting a pin into a lock assembly. The pin cannot be removed until the lock assembly is subjected to a magnetic field. The magnetic field causes displacement of a locking apparatus within the lock assembly which releases the pin.
Various tools are known for producing a magnetic field which is capable of releasing such a lock assembly. For example, U.S. Pat. No. 4,012,813 to Martens et al shows a release tool which incorporates an electromagnet for producing the desired magnetic field. The Martens et al device is quite effective for its intended purpose but has the drawback that an electrical power source must be available in order to actuate the release device. On the other hand, this type of release device can be rendered secure by simply disconnecting the power source when the device is not in use.
Another type of release tool is shown in U.S. Pat. No. 4,339,853 to Lipschitz. The Lipschitz device incorporates plural permanent magnets oriented to produce an intensified magnetic field. This intensified magnetic field acts on the locking apparatus of the fastening device. Tools using permanent magnets are quite effective and convenient; however, they suffer from a common defect that it is relatively difficult to render these devices secure since the magnetic field cannot be turned off. At the present time, in order to ensure that unauthorized personnel do not remove security tags by use of an unattended release tool, these tools are provided in portable housings which are capable of being stored in a locked cabinet or the like when not in use. This solution to the problem of security can be quite cumbersome when a lockable cabinet is not readily available in a location convenient to a checkout counter or other place where the tags are to be removed.